The pituitary gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), and the placental chorionic gonadotropin (CG) are members of a family of glycoprotein hormones, each of which is composed of two non-covalently linked, dissimilar subunits, designated alpha and beta. Detailed information is beginning to emerge concerning the cellular processes involved in the biosynthesis of the glycoprotein hormones, but little is known about the structure and organization of the gonadotropin genes or about molecular and cellular events which coordinate the complex regulation of gonadotropin subunit biosynthesis. I plan to explore these aspects of gonadotropin biosynthesis using recombinant DNA techniques. I plan to partially purify messenger RNAs (mRNAs) coding for the gonadotropin subunits from total polyadenylated RNA extracted from ovariectomized rat pituitary glands and from human placenta. This mRNA has been characterized in cell-free translation systems. Using these mRNAs as templates, I will make single-stranded complementary DNAs (cDNAs) using reverse transcriptase and then double-stranded cDNAs (ds cDNAs) using polynucleotide kinase. I will modify the ds cDNAs for insertion into the unique Pst I site of the plasmid pBR322 and clone the recombinant DNA molecules in E. coli chi 1776. I will excise the cDNA inserts for sequencing in order to elucidate the structures of the initial subunit translation products and to provide structural information on the untranslated regions of the gonadotropin subunit mRNAs. I will nick-translate the cDNA insert to high specific activity and use these probes to (i) study the structure ad organization of the genomic DNA encoding the gonadotropin subunits and (ii) measure the nuclear and cytoplasmic concentration of RNAs coding for the gonadotropin subunits under a variety of physiologic and pharmacologic influences.